Audio equipments installed in vehicles are essentially lightweight and small in size. Therefore, they can easily be stolen.
Generally small-sized and lightweight audio equipment carried in vehicles, such as radios for automobiles, have been heretofore inserted in the front panel of an automobile and rigidly fixed. However, in case of theft, such an audio equipment can be operated simply by connecting it to a power supply. In other words, the conventional audio equipment does not have its own security device, but rather relies on the security system used for the vehicle as a whole, if any. Further, such audio equipment for automobile often does not incorporate any electronic lock or similar means for protecting against theft. Thus, such audio equipment are hardly resistant to thieves. In addition, if a radio or other audio equipment is removed from the automobile without the owner's permission, a warning indicating that the equipment has an antitheft function is not given. That is, even if a thief makes contact with the equipment, the panel will not be illuminated, nor will a buzzer make a buzzing sound.